In order to acquire, improve, equip, operate and maintain a project specified in NRS 244A.057 and to ensure the payment, wholly or in part, of the general obligation bonds or revenue bonds of the county the payment of which bonds is additionally secured by a pledge of the revenues derived from any such income-producing project, flood management project or excise taxes, or any combination thereof, the board may establish and maintain, and the board may from time to time revise, a schedule or schedules of fees, rates and charges for services or facilities, or both services and facilities, rendered by or through the income-producing project or flood management project, within the corporate limits of the county, and a schedule or schedules of license or other excise taxes, in an amount sufficient for that purpose and also sufficient to discharge any covenant in the proceedings of the board authorizing the issuance of any of such bonds, including any covenant for the establishment of reasonable reserve funds.